粉末噴涂與應(yīng)用

粉末噴涂與應(yīng)用第1頁(yè)/共72頁(yè)MetalPreparation金屬的處理Pretreatmentisaprocessintendedtopreventthecorrosionofthepaintedmetal.前處理是一種提高耐腐蝕的工藝Fe2+O2+H2O = RUSTIronreactswithoxygenandwaterintheatmospherecreatingapowderybrownmess,notveryornamental,andcontinuousuntilnosolidmetalremains.鐵在空氣中會(huì)與氧氣和水反應(yīng)生成褐色的物質(zhì)第2頁(yè)/共72頁(yè)MetalPreparation金屬處理Severalmethodsofcorrosionpreventioncanbeused幾種防腐蝕的方法ForSteel:鐵：Automotiveapplications汽車業(yè)Primer:Underseals:LayersofPaint.

第3頁(yè)/共72頁(yè)Severalmethodsofcorrosionpreventioncanbeused幾種防腐蝕的方法ForSteel:鐵：ArchitecturalApplications建筑業(yè)Galvanising:AntiCorrosivePrimer*Galvanising–coveringwithalayerofzinc.MetalPreparation金屬處理第4頁(yè)/共72頁(yè)MetalPreparation金屬處理第5頁(yè)/共72頁(yè)MetalPreparation金屬處理Severalmethodsofcorrosionpreventioncanbeused幾種防腐蝕的方法ForAluminium:鋁：Aluminiumoxidisestoformawhitecorrosionproduct鋁被氧化后形成白色的物質(zhì)ArchitecturalApplications

建筑業(yè)Anodise:AcidPrimers第6頁(yè)/共72頁(yè)MetalPreparation金屬處理WhyPretreatment?為什么要前處理？Powdercoatingsareusedtoenhancetheappearanceofbuildings,machines,furniture,appliances:粉末涂料用于改善建筑，機(jī)械設(shè)備，家具，以及其它器具的表面：Designersandarchitectsaresearchingtogivedistinctionintermsofcolourandeffects.設(shè)計(jì)師和建筑師提供了包括顏色和效果在內(nèi)的標(biāo)準(zhǔn)等級(jí)Theproblemisthatallpaintsareporous：所有的涂料均不同程度的存在會(huì)滲水的小孔第7頁(yè)/共72頁(yè)MetalPreparation金屬處理Moleculesofwaterandsaltcanpenetratethroughthepaintfilm.Whentheyreachthemetalsurfacetheeffectisworsethanifthemetalisuncoated.Theanswer=Pretreatment水和鹽分子可以滲透漆膜，一旦它們與金屬表面接觸，產(chǎn)生的影響甚至比沒(méi)有噴涂還要糟糕。要解決這個(gè)問(wèn)題就需要前處理。第8頁(yè)/共72頁(yè)MetalPreparation金屬處理Pretreatment:前處理Thechemicalconversionofthemetalsurfacebeforeapplyingthepowdercoating.Themetalthenresistscorrosionandtheconversion

permanentlyimprovestheadhesionofthecoating.在使用粉末涂料以前用化學(xué)方法對(duì)金屬表面進(jìn)行處理，可以改善耐腐蝕性和增加涂層的附著力。第9頁(yè)/共72頁(yè)MetalPreparation金屬處理Theperformanceofthepowdercoatingisonlygoingtobeasgoodasthemetalpreparation.Wewillcoverthreetypesofmetaltreatmentsystems粉末涂料的功能類似于金屬處理，我們將介紹三種的金屬處理方法IronPhosphateforSteel用于鐵系的磷酸鐵ZincPhosphateforSteel用于鐵系的磷酸鋅ChromateforAluminium用于鋁的鉻酸鹽Othersystemscanbeusedandinformationisavailable.當(dāng)然還有其它處理方法第10頁(yè)/共72頁(yè)MetalPreparation–IronPhosphate金屬處理—磷酸鐵Metalpretreatmentcanbeappliedbysprayordipping.金屬前處理可以借助噴淋或浸漬Inthecaseofironphosphatetheprocesscouldlooklikethis:下面是磷酸鐵的工藝流程Stages1,2and3canbeeithersprayordip步驟1，2和3均可采用噴淋或浸漬DRAINDRAINStage1Clean&PhosphateStage2RinseStage3Rinse&SealWorkFlow第11頁(yè)/共72頁(yè)MetalPreparation–IronPhosphate金屬處理—磷酸鐵Typical3StageSystem典型的3步驟流程MetalSubstrate Steel–PhosphatisingSystem金屬基材

NoneFerrous–CleanandEtchStagetimeduration 1–90seconds不同步驟所需的時(shí)間 2–45seconds 3–30secondsStagetemperature

1，2和3步驟所需的溫度 40–60oCDrying/干燥溫度 100–120oCTypicalconcentration 2–3%byvolume典型的濃度

Typicalacidity典型的酸值

pH3.5–5.5Typicalcoatingweight 典型的膜重 20–40mg/ft.第12頁(yè)/共72頁(yè)MetalPreparation–ZincPhosphate金屬處理–磷酸鋅ZincPhosphateprocessforsteeltendstobemorecomplicated磷酸鋅的工藝流程復(fù)雜一些Stage1CleanStage2RinseStage3Phos-phateStage4RinseStage5RinseDRAINDRAINDRAINDRAIN第13頁(yè)/共72頁(yè)MetalPreparation金屬處理DwellTime:Eachstagedependson:各階段所需的時(shí)間，受下面的因素控制

Theamountofpretreatmentchemicaldissolvedinwater溶于水的前處理化學(xué)藥品的濃度

Theageofthechemical化學(xué)藥品的有效時(shí)間Regularcheckingisrequiredtogiveconsistentgoodresults–atleasttwicepershift.通常要經(jīng)常檢查前處理的狀態(tài)—一個(gè)班至少兩次第14頁(yè)/共72頁(yè)MetalPreparation–ZincPhosphate金屬處理–磷酸鋅Typical5StageSystem典型5步驟流程MetalSubstrate Steel–PhosphatisingSystem金屬基材

NoneFerrous–CleanandEtchStagetimeduration 1–90seconds不同步驟所需的時(shí)間 2–45seconds 3–60seconds 4–30seconds 5–30secondsStagetemperature溫度 40–60oCDrying干燥溫度 100–120oCTypicalconcentration典型濃度 2–4%byvolumeTypicalacidity 1=alkaline酸堿性 2=acidicTypicalcoatingweight

40–70mg/ft.典型的膜重第15頁(yè)/共72頁(yè)MetalPretreatment-BS3189Type3SprayPhosphatePlant9stagepretreatment九步法

Degrease脫脂

Rinse水洗

Rinse水洗

Rinse水洗AcidEtch(phosphoricacid)表調(diào)ZincPhosphate磷酸鋅磷化

Rinse水洗

Rinse水洗

De-ionisedwater去離子水水洗

Dry干燥QualityStandard

BS6497參考英國(guó)標(biāo)準(zhǔn)BS6497第16頁(yè)/共72頁(yè)MetalPretreatment

–QualityControl金屬前處理–質(zhì)量控制TitrationChecks:檢測(cè)項(xiàng)目：

1.Cleaner 2.Rinses 3.AcidConcentration 4.Rinse 5.PhosphateConcentrationandcoatingweight 7.Rinse 8.ObservationsCheckedatregularintervalsduringnormalproductionandbeforeproductioncommences以上項(xiàng)目應(yīng)在生產(chǎn)過(guò)程中定時(shí)和生產(chǎn)前進(jìn)行檢驗(yàn)第17頁(yè)/共72頁(yè)MetalPretreatmentDry金屬前處理干燥Toensuremetalsurfaceisdryreadyforpowdercoating.在噴涂粉末涂料前必須保證金屬工件已經(jīng)完全干燥Dryingoven-PhosphatePlant第18頁(yè)/共72頁(yè)MetalPreparation–Chromate金屬處理—鉻酸鹽Foraluminium–chromateconversion鋁—鉻酸鹽處理BritishStandardsexistfortheconversionofaluminium–

BS6496適用于鋁的英國(guó)標(biāo)準(zhǔn)BS6496ThesameconversioncanbeusedforGalvanisedsteel--BS6497適用于電鍍鐵的英國(guó)標(biāo)準(zhǔn)BS6497Stage1CleanStage2RinseStage3EtchStage4RinseStage5Chrom-ateStage6–7RinseStage8DeminRinseDRAINDRAINDRAINDRAINDRAINDRAIN第19頁(yè)/共72頁(yè)MetalPreparation–Chromate金屬處理—鉻酸鹽Typical7StageSystem七步法MetalSubstrate Aluminium/AluminiumAlloys金屬基材

GalvanisedSteel–CleanandEtchStage1 CleaningStage2 RinseStage3 DeoxidisemetalsurfaceStage4 RinseStage5 ChromateStage6 RinseStage7 AcidulatedRinseStageTemperature 80–100oCDrying 90–95oCDonotoverheatatthedryoffstage干燥溫度不能過(guò)高第20頁(yè)/共72頁(yè)MetalPreparation–Chromate金屬處理—鉻酸鹽ChromateconversiontoAluminiumandGalvanisedsteel鉻酸鹽處理完鋁和電鍍鐵后的變化YellowChromateConversion TypicalCoating黃色鉻酸鹽的變化 Weight(g/m2)PaleYellow 0.2–0.7Gold 0.7–1.6Brown 1.6–3.5Greenmixchromate/phosphate 0.5–2.0

ForPowderCoatingalightweightcoatingisrecommendedIntherange0.2–2.0g/m2應(yīng)用于粉末涂料，膜重一般在0.2—2.0g/m2第21頁(yè)/共72頁(yè)SprayingandApplicationofPowderCoatings粉末涂料的噴涂與應(yīng)用第22頁(yè)/共72頁(yè)第23頁(yè)/共72頁(yè)第24頁(yè)/共72頁(yè)P(yáng)owderApplicationSystems粉末涂料的應(yīng)用系統(tǒng)第25頁(yè)/共72頁(yè)P(yáng)owderApplicationSystems

FeedSystems粉末涂料應(yīng)用系統(tǒng)供粉系統(tǒng)DirectfeedsystemfromDrumtoGun.粉末涂料直接從粉桶送至噴槍Thesystemshownfeeds1gun右圖是只供一個(gè)噴槍的直接供粉系統(tǒng)第26頁(yè)/共72頁(yè)P(yáng)owderApplicationSystems

FeedSystems粉末涂料應(yīng)用系統(tǒng)供粉系統(tǒng)Directfeedsystemdirectlyfroma25kilobox.Thissystemissetuptofeed2guns.Usedmainlyinmanualoperations.右圖為直接從粉末涂料的包裝箱至噴槍的供粉系統(tǒng)。圖中的設(shè)備適用于兩把噴槍，通常用于人工噴涂。第27頁(yè)/共72頁(yè)P(yáng)owderApplicationSystems

FeedSystems粉末涂料應(yīng)用系統(tǒng)供粉系統(tǒng)Bulkfeedsystem,powderissuppliedinafibrebag.Weightofpowder–upto1,000kilosperbag.Usedmainlyonautomaticplantswherecolourchangeislimited.大型供粉系統(tǒng)，粉末涂料一般1噸一個(gè)包裝，用于自動(dòng)噴涂系統(tǒng)，限于換色較少的場(chǎng)合。第28頁(yè)/共72頁(yè)P(yáng)owderFluidisationSystems粉末涂料流化系統(tǒng)Dryairpassesthroughamembranegivingthepowderliquidqualities.干燥的空氣通過(guò)微孔板，使粉末涂料象水一樣流動(dòng)。Theairmustbedryandfreefromwaterandoil.空氣必須除水和油第29頁(yè)/共72頁(yè)P(yáng)owderDeliverySystems粉末涂料的傳送系統(tǒng)第30頁(yè)/共72頁(yè)P(yáng)owderDeliverySystems粉末涂料的傳送系統(tǒng)ActualpowderfeedsystemVenturifeedfromfluidbed.右圖是用文氏管從流化床吸取粉末的送粉系統(tǒng)第31頁(yè)/共72頁(yè)ForcesatworkonthePowderParticlesAtanyonetime4forcesareatworkonthepowderparticleasittravelsfromtheguntotheearthedwork-piece.粉末在離開(kāi)噴槍到達(dá)工件時(shí)受4種力的影響AirResistanceElectrostatic AttractionWeight(Gravity)AerodynamicForce第32頁(yè)/共72頁(yè)P(yáng)owderChargingSystemsThereare2majorcategoriesinchargingofpowdercoatingcoronaandtribo:粉末涂料主要有兩種帶電方法—靜電/摩擦GunType ChargeLocation充電位置 Internal External Remote PowderSupply X XCorona靜電法

IntegratedGun PowderSupply X XTribo 摩擦帶電法

X第33頁(yè)/共72頁(yè)CoronaChargingSystems靜電帶電系統(tǒng)Inthismethod,ahighvoltagegeneratorisusedtochargeanelectrodeatthetipwhichcreatesanelectrostaticfield(orcorona)betweenthegunandthework-piece.利用高壓電極使粉末帶電，并在噴槍與工件間形成電場(chǎng)ExternalChargingSystem/外充電系統(tǒng)第34頁(yè)/共72頁(yè)CoronaChargingSystems靜電帶電系統(tǒng)Coronacharging -manualsystem/手動(dòng)槍

-automaticsystem/自動(dòng)槍第35頁(yè)/共72頁(yè)CoronaChargingSystems靜電帶電系統(tǒng)InternalChargingSystem內(nèi)充電系統(tǒng)第36頁(yè)/共72頁(yè)CoronaNozzleSystems靜電槍的噴嘴ThetypeofproducttoBecoatedwillinfluenceThenozzletobeusedontheSpraygun,twotypesareshown第37頁(yè)/共72頁(yè)CoronaNozzleSystems靜電槍的噴嘴ConicalSprayNozzles–usedtogiveanevenlydistributedfilmthicknessoverflatpanels.圓錐型的噴嘴一般用于噴涂平面，并得到膜厚均勻的涂層。InterponAFparticlemanagedpowderbeingappliedondomesticappliances.右圖為InterponAF粉末涂料用于家用設(shè)備第38頁(yè)/共72頁(yè)CoronaChargingSystems靜電帶電法Thehighvoltagepowersupplychargestheelectrode高壓發(fā)生器使噴槍電極帶電Theconcentratedchargecreatesanelectrostaticfield帶上電荷后形成靜電場(chǎng)Theelectrostaticfieldcausestheairtoionizeandgenerateacorona靜電場(chǎng)使空氣電離形成電暈Thecoronaemitselectrons電暈放射出電子Theelectronsarepickedupbyoxygenmoleculesformingnegativeions這些電子借助氧分子形成負(fù)離子第39頁(yè)/共72頁(yè)CoronaChargingSystems–cont.靜電帶電法Theionsfollowthefieldlines負(fù)離子沿著電力線移動(dòng)Thepowderparticlesdistortthefieldaroundthem粉末涂料粒子使周圍的電力線產(chǎn)生扭曲Thedistortedfieldlinesdirectionstothepowderparticles扭曲后的電力線引導(dǎo)離子被粉末涂料粒子吸附

Theionsbombardthepowderparticlesandtransfertheelectronsgivingtheparticlesanegativecharge吸附的離子轟擊粉末粒子，并使其帶上負(fù)電，形成負(fù)極第40頁(yè)/共72頁(yè)TriboChargingSystems摩擦帶電法Triboelectricityisgeneratedbythefrictionofonematerialonanother.InTribochargedsprayguns,thepowderrubsonaspeciallyformulatedandshapedsurfacewhichallowschargetotransfer.摩擦帶電是通過(guò)不同物質(zhì)摩擦形成的，摩擦槍可以使粉末與特殊設(shè)計(jì)并有特殊結(jié)構(gòu)的表面摩擦而帶電第41頁(yè)/共72頁(yè)TriboChargingSystems摩擦帶電法第42頁(yè)/共72頁(yè)TriboChargingSystems摩擦帶電法Tribonozzlesindifferentconfigurations.不同結(jié)構(gòu)的摩擦槍噴嘴第43頁(yè)/共72頁(yè)ElectrostaticFluidBedSystems靜電流化床法第44頁(yè)/共72頁(yè)P(yáng)owderPenetration粉末的吸附Thepictureshowsthedevelopmentofthecorona(reddottedarea).Articlespassingthrougharechargedwiththenegativeions(-).Thechargedpowderparticlesareattractedtotheearthedsubstrate.右圖顯示了電場(chǎng)，電力線，粉末的充電及被接地的工件吸附過(guò)程。第45頁(yè)/共72頁(yè)P(yáng)owderPenetration粉末的穿透Achievingpenetrationintodeeprecessesinmostimportantwhenapplyingpowdercoating.粉末涂料能否到達(dá)死角這對(duì)粉末涂料的應(yīng)用來(lái)說(shuō)很重要ThemosteffectivecontrolsarethenozzlepatternAndairassistance.有效的控制方法是選擇合適外形的噴嘴及調(diào)整輔助空氣Itispossibletoovercomethe“FaradayCageEffect”現(xiàn)在，克服“法拉第”效應(yīng)已成為一種可能第46頁(yè)/共72頁(yè)P(yáng)owderPenetration粉末的穿透Reducingthe“FaradayCage”Effect減弱“法拉第”效應(yīng)ToreducetheeffectitisnecessaryToassistinthecreationofchargedairParticlesinsidetherecess.Thisshouldbe徹achievedbyincreasingtheairstream.可以借助加大傳送空氣的壓力來(lái)減弱“法拉第”效應(yīng)第47頁(yè)/共72頁(yè)FaradayCageEffect“法拉第”效應(yīng)

AFaradaycagecantechnicallybedefinedasanareawithinwhichthereisnoelectrostaticfield. Infinishing,thistermisappliedmoreloosely,andgenerallyreferstoanareasuchasinsidecornersorcavitiesthataredifficulttocoat. Thereasonwhytheseareasaredifficulttocoatisthattheadjacentsurfacestotheinsideofthecornerattracttheelectrostaticfiled,thereforedeflectingthepowderfrompenetratingintotherecessedareas. Atthesametime,thisrecessedareaisdifficultfortheaerodynamicforcestopenetrateintowithoutblowingpowderoffalreadycoatedareas.

法拉第區(qū)域可以被認(rèn)為是靜電屏蔽區(qū)。實(shí)際應(yīng)用中定義更寬松，通常是指死角和洞等難噴涂區(qū)域。難噴涂的原因是這些區(qū)域的外圍吸引了電荷，這樣粉末就不能被吸附。另外，從空氣動(dòng)力學(xué)來(lái)將，輸送空氣將粉末吹至這些區(qū)域也很難。第48頁(yè)/共72頁(yè)BackIonisation反彈效應(yīng)A=powderattractedtotheearthedcomponentB=builduptocorrectfilmthicknessC=ionisedairwithinthepowderfilmrepelsoncomingparticles

A=粉末吸附在接地工件B=形成合適的膜厚C=在涂層上的離子云抵制吸附帶有同類電荷的粉末第49頁(yè)/共72頁(yè)P(yáng)owderRecoveryIntegratedSystem粉末回收系統(tǒng)IntegratedSpray/RecoveryBoothSystem完整的噴涂/回收系統(tǒng)第50頁(yè)/共72頁(yè)P(yáng)owderRecoverySystems粉末回收系統(tǒng)Typicalcartridgeback-Pulsecleaningdesign.UsedincartridgeRecoverysystems.典型脈沖自清理設(shè)計(jì)，通常適用于桶狀回收系統(tǒng)第51頁(yè)/共72頁(yè)P(yáng)owderRecoverySystems粉末回收系統(tǒng)CycloneRecoverySystemThecycloneisusedtoseparatethepowderparticlesfromtheair.Theairisdrivenroundthesidesofthecyclone,reducinginvelocityandreleasingthepowdertobecollectedatthebase.Finepowderisusuallytransportedoutofthecycloneontheairflow.旋風(fēng)分離器根據(jù)粒徑分離粉末，空氣沿著旋風(fēng)分離器壁做圓周運(yùn)動(dòng)，速度漸漸降低，并釋放被收集的粉末至底部。細(xì)粉通常會(huì)隨流動(dòng)空氣離開(kāi)旋風(fēng)分離器。第52頁(yè)/共72頁(yè)P(yáng)owderRecoverySystems粉末回收系統(tǒng)Finepowderiscollectedonafiltersysteminthe“afterfilters”.Thepneumaticairpulseensuresairflowisconsistentandthefinepowdercollectedfordisposal.細(xì)粉通過(guò)濾芯濾層被收集。有力的氣體脈沖保證了空氣流動(dòng)的連續(xù)性及需被分離的細(xì)粉收集。

第53頁(yè)/共72頁(yè)P(yáng)owderRecoverySystems粉末回收系統(tǒng)Amotorgeneratestheairflow.Ensuringthecorrectairvolumeandvelocityismaintained.電機(jī)提供流動(dòng)空氣，并保證氣體流量和速度。第54頁(yè)/共72頁(yè)P(yáng)owderin-lineSievingSystems粉末過(guò)篩系統(tǒng)RotaryIn-LineSieve旋轉(zhuǎn)篩第55頁(yè)/共72頁(yè)P(yáng)owderVibratingSievingSystems震動(dòng)篩Vibratingsievesaredesignedtoworkeither: -Freestanding -In-line震動(dòng)篩適用于： -獨(dú)立區(qū)域 -流水線第56頁(yè)/共72頁(yè)P(yáng)owderReciprocatorCycle粉末噴涂的往復(fù)機(jī)構(gòu)CycleRate往復(fù)速度=No.OfGunsxPitchofGunsx60噴槍數(shù)量x噴槍位置x60ConveyorSpeed(mm/min)傳送鏈速度（毫米/分鐘）Thiswillensurestriationsdonotoccuronthecomponentsbeingcoated.在噴涂中要保證不要形成帶狀涂層。第57頁(yè)/共72頁(yè)ApplicationPractical實(shí)際應(yīng)用第58頁(yè)/共72頁(yè)StovingandCuringofPowderCoatings固化爐及粉末涂料的固化第59頁(yè)/共72頁(yè)TypesofOven固化爐的類型Convection–energyistransmittedbyaircirculationtoheatthecomponents對(duì)流–熱量通過(guò)空氣流動(dòng)傳送，加熱工件Radiation–energyistransmitteddirectlyontothepartswithoutheatingairbetweenthepartsandtheradiationsource輻射–熱量直接從輻射源被傳送至工件而無(wú)需空氣作媒體Induction–energyistransmittedthroughinducingelectricaleddycurrentsthatgenerateheatinthemetalparts感應(yīng)–熱量借助電流來(lái)傳送來(lái)加熱金屬工件第60頁(yè)/共72頁(yè)TheBakingProcess固化過(guò)程Thebakingstage,duringwhichthepowdercoatingmelts,flows,gelsandfinallychemicallyreacts(cross-linking)andcures.Itiscriticaltotheperformanceofthecoatingthatthetemperatureandtimeattemperaturearemaintained.Mostbakingovensaredesignedtotakethesubstratethroughapre-programmedtime–temperatureprofile.固化過(guò)程包括粉末的熔融，流平，凝膠最后發(fā)生化學(xué)反應(yīng)形成涂層。固化溫度極其所占時(shí)間是非常重要的，大多數(shù)固化爐借助預(yù)先設(shè)置固化時(shí)間（溫度曲線）來(lái)設(shè)計(jì)。第61頁(yè)/共72頁(yè)P(yáng)owderApplicationRadiationStoving粉末的輻射固化GasfiresInfra-Redovenusedforindustrialcomponents.左圖為用于固化工業(yè)用品的瓦斯紅外爐I-Remittersinsidetheovencurethepowderfilmwhenindirectline,asradiationenergy.右圖為通過(guò)爐內(nèi)紅外發(fā)生器（熱源）固化粉末涂料I-Risoftenusedtoboostthecuringinfrontofaconventionalaircir